Module aims
- Provide an outline of the menstrual cycle and the hormones involved, including what you can expect during the primary three phases (follicular phase, ovulation, luteal phase)
- Deliver insight on how the menstrual cycle may influence training and performance according to the latest research
- Describe the signs and symptoms of menstrual irregularities and highlight when to seek further help from a medical practitioner
Summary
- The menstrual cycle is more than just a period, it’s a complex interaction of hormones with three primary phases (the follicular, ovulation and luteal phase).
- A normal menstrual cycle is between 21-35 days in length, occurs on a regular schedule, and includes 3 to 7 days of menstrual bleeding around ~50mL in volume.
- The menstrual cycle can influence athletic performance, although its effect can vary between athletes, highlighting the importance of tracking your period.
- Tracking your period is important as an athlete and can be managed in many ways including on paper, or via one of our recommended applications.
- You should seek the advice of a specialised women’s health GP if you experience any of the undesirable signs and symptoms outlined.
What are the important hormones involved in a menstrual cycle?
Estrogen and progesterone are two of the most important hormones in the female body, both playing critical roles in the normal reproductive development and function of your body. Your ovaries produce most of your estrogen and progesterone during your reproductive years. Your adrenal glands also release small amounts of estrogen and progesterone and, should you become pregnant, your placenta will too.
Note, while they are often thought of as ‘female hormones’, they are also found in men.
Estrogen
- Produced by developing follicle before ovulation
- Important for bone strength and cardiovascular health
Progesterone
- Controls the lining of the uterus
- Prepares the uterus for fertilisation of the egg
- Maintains a pregnancy for the first 10 weeks
The amount of estrogen and progesterone in your body will vary over time with fluctuations linked with certain points in the menstrual cycle, after childbirth and throughout menopause. It has been suggested that the hormonal fluctuations of estrogen and progesterone during the menstrual cycle affect a swimmer’s physiology and performance. This is due to the numerous effects on these hormones have on the cardiovascular, respiratory, metabolic and thermoregulatory parameters.
Estrogen
- Helps regulate body temperature
- Supports stronger bones
- Can influence muscle glycogen and fat utilisation
Progesterone
- Regulates blood pressure
- Helps support healthy thyroid hormone activity
The menstrual cycle is more than just a period; it is a complex pattern of changes within the ovaries and uterus preparing the body for a possible pregnancy. These changes are regulated by the complex interaction of hormones including luteinising hormone (LH), follicle-stimulating hormone (FSH), estrogen and progesterone throughout the duration of your menstrual cycle.
Phases of a menstrual cycle
The follicular phase typically occurs between day one and day 12 of the average 28-day cycle. If you do not have a typical 28-day cycle, the follicular phase can be established by first establishing your luteal phase and working backwards (whole cycle length – luteal phase length = follicular phase length).
Within your body, the follicular phase involves the maturation of the ovarian follicles and preparation for the release of an egg. During the first few days of the cycle, several follicles are stimulated due to a rise in follicle-stimulating hormone (FSH).
What to expect:
Low estrogen, low progesterone
- Fatigue (i.e., feeling lethargic or unmotivated)
- Menstrual bleeding (~Day 1-7)
- Light period cramps that do not impact your day
Ovulation typically occurs between day 12 and day 15 of an average 28-day cycle and involves the release of a mature egg from the follicle. As not everyone has a 28-day cycle, ovulation may occur on different days of the cycle for different women. If you would like to learn when you ovulate for fertility reasons, we recommend contacting an Ignite Athlete specialised women’s health GP today. This occurs as the developing follicle causes a rise in estrogen which prompts the anterior pituitary gland to produce a surge of luteinising hormone (LH).
If sperm are present in the fallopian tube at the time of ovulation, the egg may be fertilised and commence the process of embryo development. This may result in pregnancy if the developing embryo reaches the uterus and implants into the endometrium. If the egg is not fertilised within 12 to 24 hours of ovulation, it will dissolve and be absorbed in the fallopian tube.
What to expect:
High estrogen, low progesterone
- You might experience twinges of pain (sign of ovulation)
- Increase in core temperature
The luteal phase typically starts after ovulation around day 15 during the average 28-day cycle. If you do not have a typical 28-day cycle, your luteal phase can be determined by backtracking 14 days from your first day of bleeding.
During the luteal phase the follicle in the ovary that produced the egg becomes the corpus luteum. The corpus luteum produces the hormones progesterone and estrogen to provide nutrition to the endometrium, the lining of the uterus.
If an embryo has successfully implanted into the endometrium, human chorionic gonadotropin (hCG) is produced. The production of hCG causes the ovary to continue producing progesterone which is necessary to support the pregnancy. Alternatively, if there is no fertilisation or implantation, the ovary ceases producing progesterone resulting in the uterine lining shedding and the start of a period.
What to expect:
High estrogen, high progesterone
Most people also experience symptoms in the days leading to their menstrual period which are referred to as premenstrual syndrome (PMS) symptoms. This can vary between people and each menstrual cycle with common symptoms experienced include, but are not limited to:
- Headaches
- Skin changes
- Food cravings
- Mood changes
- Abdominal bloating
- Changes in sleep
- Changes in sexual desire
- Breast tenderness, swelling and/or pain
What’s normal for a menstrual cycle?
- Cycle length: 21-35 days that occurs on a regular schedule
- Menstrual bleeding length: 3-7 days with no large clots (i.e., no clots larger than a 10-cent piece)
- Menstrual bleeding amount: approximately 50 mL (2-3 tablespoons) total – e.g., no flooding of pads or changing tampons every hour
How to track your menstrual cycle
Tracking your menstrual cycle and monthly changes regularly can empower you to better understand what’s happening in your body and provide you with a wealth of knowledge about your overall health.
Menstrual cycle tracking has many benefits as it allows you to identify any menstrual abnormalities, and ensure your training is working with your cycle.
One benefit of period tracking is that it helps you get to know what is normal and what isn’t for you. As a result of having a better understanding of the typical cyclical symptoms you experience, you should be able to identify any changes and/or abnormalities in your cycle which may require you to seek the advice of a professional.
The tracking log can also serve to assist your doctor in getting a more comprehensive idea of your menstrual cycle, helping them to better understand your individual circumstances.
Tracking your menstrual cycle also gives you the ability to understand how your training is influenced by your cycle and prepare yourself for any competitive goals. Understanding your cycle, as well as any symptoms associated with it, gives you the ability to understand how your current training, recovery and hydration practices work with or are influenced by your cycle.
This is an area of increasing research interest. Currently, there is variability and individuality in the research associated with the age of the athletes, sport they are playing and stage of their career. However, there is some evidence you may perform and recovery differently and be more susceptible to injury at different times of your cycle. As a result, starting to understand your cycle will allow you to consider how your current training and lifestyle is influenced by your cycle and how you can adjust these elements to optimise performance of you.
Noting down the start date of each period is a great starting point when tracking your period as this allows you to follow the pattern of your cycle. The first day of your period is the first day of your menstrual bleeding. For a more comprehensive picture of your menstrual cycle, we also recommend you consider the following questions when logging your menstrual cycle:
- Have you experienced any premenstrual syndrome (PMS) symptoms?
- When did menstrual bleeding begin?
- How many days did your period last?
- Have you experienced any bleeding between periods?
- What symptoms did you experience during your period?
There are also a variety of period tracking apps available that can help you track everything from your period length to the PMS symptoms you may be experiencing. Period tracking apps we recommend include:
- Garmin Connect– Menstrual cycle tracking
- Apple Cycle Tracking app
- FitR woman
- Flo
Please note, the advice provided on many applications may be inaccurate or not directed to athletes’ priorities. The applications are best used to gain understanding of each individual athlete’s cycle and provide a convenient way to track and record your period at various times.
How does it influence athletic performance?
The effect of the menstrual cycle on athletic performance is being increasingly recognised as a key consideration for women’s sport. Menstrual-related symptoms are highly prevalent and highly individualised in female athletes. For many athletes, the effects of their menstrual cycle can impact various aspects of their training, competition, and daily life.
The menstrual cycle has been suggested to affect physical performance due to various mechanisms such as altered thermoregulation, substrate metabolism, muscle activation and body composition.
However, the current research variable and individualised to the different types of athletic groups (i.e., amateur vs elite) and within different sports and age groups. While research continues to grow in this area, each athlete may perceive their performance and training to be different in each phase and may not necessarily experience all these impacts at the same level. This is why tracking your menstrual cycle and documenting how you think, feel, train, and perform at different stages is so important to see how your body responds.
Nevertheless, current research suggests some athletes may experience the following effects:
Follicular phase
- Variable changes in aerobic and endurance performance
- Possible increase in perceived performance
- Possible increase strength in 1RM testing
Ovulation
- Enhanced anaerobic performance
- Possible enhanced strength and power
- Risk of decreased endurance performance
- Risk of poor technique due to reduced proprioception
Luteal phase
- Enhanced endurance
- Greater ventilation
- Increased resting core body temperature
- Increased body mass due to fluid retention
- Decreased anaerobic performance
- Possible risk of PMS symptoms diminishing performance in late luteal phase
When to see a doctor?
We recommend you seek the advice of a specialised women’s health General Practitioner (GP) if you experience any of the following:
- Significant changes in the pattern of your period
- The absence of a period
- Heavy bleeding (e.g., flooding of pads, changing pad/tampon every hour etc.)
- Large clots present during your period
- Severe pain that impacts on your daily activities
- Vomiting or nausea
- Blood in urine or bowel motion
- Urinary incontinence
They will assess your symptoms, and where relevant, refer you onto a gynaecologist for further investigation.
If you have concerns about your menstrual cycle, we encourage you to get in touch with us. We have a network of specialised General Practitioners, gynaecologists and fertility specialists across Australia who will be more than happy to speak with you and discuss your individual circumstances.
With over 50 dedicated specialists across 70 consulting locations throughout the country, our friendly staff can help you choose the right medical professional to guide you and help you achieve your sporting goals.
